Length Of Barrel Research Articles

Visualization of the granule temperature using thermal imaging to improve understanding of the granulation mechanism in continuous twin-screw melt granulation

The aim of this study is to increase process understanding of the granulation mechanism in twin-screw melt granulation by evaluating the influence of different screw configurations on granule formation and granule temperature via thermal imaging. The study used a Design of Experiments (DoE) to process a miscible and immiscible formulation (85% API/binder w/w) using a twin-screw extruder with varying screw configurations. The barrel temperature (°C), screw speed (rpm), throughput (kg/h), and kneading zone (direction and stagger angle) were varied. Granule and process properties were evaluated for samples collected at four different locations along the length of the granulation barrel to visualize the granule formation, and granule temperature was monitored by an infrared camera to measure heat transfer on the granules. The resulting temperature was linked to the granule properties and the granule formation along the length of the barrel. The most influencing factors on the granule temperature are the direction of the kneading zone and the set barrel temperature. It was observed that granule formation mainly occurred in the zones that apply more kneading on the granules. The highest temperature increase was observed when the smallest stagger angle in reverse configuration was used, and could be linked to better granule quality attributes.

Electromagnetic launcher for heavy projectiles

In this paper, we present the electromagnetic launcher with capacitive power source of 4.8 MJ. Our installation allows studying of the projectile acceleration in railgun in two regimes: with a solid armature and with a plasma piston. The experiments with plasma piston were performed in the railgun with the length of barrel of 0.7-1.0 m and its inner diameter of 17-24 mm. The velocities of lexan projectiles with weight of 5-15 g were in a range of 2.5-3.5 km/s. The physical mechanisms that limit speed of throwing in railgun are discussed.

Generation of Calibration Charts for Horizontal Petroleum Storage Tanks Using Microsoft Excel

Petroleum and petroleum products are expensive commodities due to their global demand as a major source of energy. As a result of its expensiveness, there is need for proper inventory to know what is going in and coming out of the storage tanks. Proper inventory is achieved by accurate measurement through the generation of a calibration chart for every storage tank. Calibration chart (tank table) gives the needed information about the level (height) and the corresponding volume of the petroleum product in the storage tank. Geometrical method (dry calibration) is the most widely used method of computing tank table using the field data such as circumference, shell or plate thickness, length of barrel and lap/butt strap while taking the necessary correction factors into consideration. Microsoft Excel is a powerful tool in Microsoft (MS) office package used for computation and programming through the use of visual basic for application. In this study, MS Excel was used to generate two different charts which were compared with the charts generated from customized specialized calibration software from Societe Generale de Surveillance (SGS software) and the results were found to be within the statistical controlled limit.

In-depth experimental analysis of pharmaceutical twin-screw wet granulation in view of detailed process understanding

Twin-screw wet granulation is gaining increasing interest within the pharmaceutical industry for the continuous manufacturing of solid oral dosage forms. However, limited prior fundamental physical understanding has been generated relating to the granule formation mechanisms and kinetics along the internal compartmental length of a twin-screw granulator barrel, and about how process settings, barrel screw configuration and formulation properties such as particle size, density and surface properties influence these mechanisms. One of the main reasons for this limited understanding is that experimental data is generally only collected at the exit of the twin-screw granulator barrel although the granule formation occurs spatially along the internal length of the barrel. The purpose of this study is to analyze the twin-screw wet granulation process using both hydrophilic and hydrophobic formulations, manufactured under different process settings such as liquid-to-solid ratio, mass throughput and screw speed, in such a way that the mechanisms occurring in the individual granulator barrel compartments (i.e., the wetting and different conveying and kneading compartments) and their impact upon granule formation are understood. To achieve this, a unique experimental setup was developed allowing granule characteristic data-collection such as size, shape, liquid and porosity distribution at the different compartments along the length of the granulator barrel. Moreover, granule characteristic information per granule size class was determined. The experimental results indicated that liquid-to-solid ratio is the most important factor dictating the formation of the granules and their corresponding properties, by regulating the degree of aggregation and breakage in the different compartments along the internal length of the twin-screw granulator barrel. Collecting appropriate and detailed experimental data about granule formation along the internal length of the granulator barrel is thus crucial for gaining fundamental physical understanding of the twin-screw wet granulation process.

A Miniature Device for Shock Initiation of Hexanitrostilbene by High‐Speed Flyer

AbstractA miniature device for shock initiation of the hexanitrostilbene (HNS) through micro‐charge detonation‐driven flyer was fabricated. This device consisted of the substrate, micro‐charge, flyer, and barrel. Four types of flyer (titanium of 28 μm, aluminum of 22 μm, copper of 22 μm and polyimide (PI) of 55 μm in thickness) were studied and the effect of micro‐charge thickness, diameter, and barrel length were investigated by measuring the average flyer velocities using polyvinylidene fluoride (PVDF) films. The results show that the titanium flyer is more proper for such initiation device compared to aluminum, copper, and polyimide flyer. The average velocity of the flyer increased with the thickness of micro‐charge and the increment was larger when the thickness increases from 0.3 mm to 0.4 mm than when the thickness increases from 0.4 mm to 0.6 mm. The flyer velocity significantly increased with the increase in the diameter of micro‐charge until a plateau appeared at 0.8 mm. The flyer velocity increased first and then decreased sharply with the increase in barrel length. The average velocity for a 28 μm thick titanium flyer was measured to be as high as 2468 m s−1 when the thickness, micro‐charge diameter and the length of barrel were 0.6 mm, 0.8 mm and 659 μm, respectively. The HNS‐IV explosive with density 1.57 g cm−3 was initiated by this miniature device.

Twin screw granulation: Understanding the mechanism of granule formation along the barrel length

The objective of this study was to develop a detailed understanding of the roles and effects of the screw elements in the granule formation along the length of barrel in the twin screw granulator (TSG) by incremental addition of the elements in the screw configuration. The number of kneading and conveying elements in the screw configuration, liquid to solid ratios (L/S) and screw speeds were varied while studying their effects on the mechanism of granule formation and the granule attributes (size, shape and structure). In order to study the granule formation mechanism, the length of TSG barrel was divided into 10 Parts. This was done to mimic and understand the actual granulation process that occurs in the individual Parts (sections) when total barrel length (cumulative length of all 10 Parts) comprising both conveying and kneading zones in the screw configuration is used. Part-1 consisted two long pitch conveying elements (LPCE) followed by four short pitch conveying elements (SPCE). Part-2 consisted of two kneading elements (KE) placed at the end of the granulator after 4SPCE. Similarly, Part-3 to Part-7 subsequently consisted 4, 6, 8, 10 and 12KE. In Part-8, 2SPCE were placed next to 12KE which is named as 12KE+2SPCE. Same thing was repeated for Part-9 with 4SPCE and Part-10 with 6SPCE. In a separate experiment, last 4SPCE in Part-10 were replaced by 2LPCE to study the effect of increase in the screw channel width on the granule size and structure.It was found that the granules became bigger in size, elongated and denser with increasing number of KE (Part-2 to Part-7) due to increase in shear and compaction forces acting on them. The influence is more evident at higher L/S. However, the presence of SPCE in addition to the KE (Part-8 to Part-10) reduced the size and elongation of granules due to the shearing and cutting action of SPCE. The granule formation and growth in the TSG was found to be the function of the type and number of elements in the screw configuration and the L/S. Presence of 2LPCE at the end of the screw configuration resulted in an increase in the granule size and structural voids due to the coalescence or re-agglomeration of granules.

Modern Trend of Country Made /Improvised Pistols Used in the Capital of India

Now a days crimes relating to firearms and ammunition have dramatically increased in northern part of India. It has been observed that Country made pistols of 8mm/.315” bore; Improvised pistols of 7.65mm/9mm calibre, .32”/.38” calibre are randomly used by criminals in Delhi and NCR regions. On the basis of crime cases received in the Forensic Science Laboratory for examination, the smooth bore illegal country made firearms chambered for pistol, revolver and rifle cartridges are very often encountered in criminal cases all over India and other developing countries. The possibility of identifying types of smooth bore firearms of country made and improvised pistols has been studied. On analysis of crime cases received for forensic examination, it has been found that 75% crimes are committing by 8mm/.315” calibre by country made pistols, 20% by 7.65mm calibre/bore improvised pistols and remaining 5% crime by other firearms like 12 bore country made pistol, .32”/.38” calibre/bore improvised pistols. In present study, firearms details relating to length of barrel, total length of firearms, internal diameter of barrel at muzzle end and breech end have been studied in view of forensic significance and may be useful for Forensic scientists, Law Enforcement Agencies, Police Officers and Judicial Officers etc.

Modular 12 Gauge Shotgun Beanbag Accuracy Study

Abstract As with all less-than-lethal weapons, the user is frequently left to estimate the optimum effective range of their weapon. Factory literature often exaggerates effective ranges and other features, which can be misleading and potentially dangerous in the deployment of the weapon. Using a modular combat shotgun and its three barrels, this study examined the accuracy of 12 gauge bean bag rounds in relation to barrel length. Accuracy was measured by point of impact and projectile spread in relation to the deviation from the point of aim. Our observations for the selected shotgun and bean bag rounds show that, at distances under 12 m (40 ft), the projectile was both accurate and reliable. At greater distances, both accuracy and reliability decreased. The 25 cm (10 in), 36 cm (14 in), and 46 cm (18 in) barrels can be used in close proximity from 3 m (10 ft)—15 m (50 ft) without a considerable loss of accuracy. This is of major significance as the use of shotguns during tactical room clearing is often limited by the length of barrel. These findings suggest that even the shortest length barrel tested would perform well if the targets are not engaged beyond 15 m (50 ft). Beyond this distance, the 46 cm (18 in) barrel is the most accurate performer and will reliably engage targets out to the maximum tested range of 24 m (80 ft).

A generalized theory linking barrel fill length and air bubble entrapment during extrusion of starch

A theory linking barrel fill length and air bubble entrapment during extrusion of starch has been proposed. Experimental data suggested that when barrel fill length (defined as length of barrel filled with material pressurized to at least 689 kPa) was greater than the melting region-to-die barrel distance, then air bubble entrapment (as measured by porosity) in the unexpanded extrudate was favored; if the reverse was true, then air bubble entrapment was hampered. Bubble number density in the unexpanded extrudate was not only a function of the total entrapped air (porosity) but also of the type of starch used (pregelatinized versus native amylopectin) where pregelatinized amylopectin gave much higher bubble number density values than the native counterpart. Screw speed increased bubble number densities at constant entrapped air, which seemed to suggest bubble break-up by increased shear of the rotating screws.

Some Factors Affecting the Intonation of a Clarinet

Experimental data are presented showing the characteristic intonation of a soprano clarinet and how it is affected by ambient temperature, stiffness of reed, length of barrel, and gap adjacent to barrel. An increase of ambient temperature of 10°C raises the intonation 0.09 semitone (9 cents). A stiff reed may make the intonation 15 cents higher than does a soft reed. An increase in barrel length of 4 mm lowers the “bell” notes by 10 cents, but notes an octave higher are changed twice as much: the intonation is distorted. The inside gap resulting from pulling the barrel from the upper joint does not lower the intonation uniformly; notes of the transition register are affected much more than others. Flexibility of intonation varies throughout; high notes can be modified markedly; notes produced by greater length of tube are less flexible. There is a tendency for notes near the center of the chalumeau register to be relatively sharp; this tendency is associated with the use of a single register hole for the entire clarion register.